added `snippet: boolean` option

This release adds a feature to address #1882

Sometimes you don't want Browsersync to auto-inject it's connection snippet into your HTML - now you can disable it globally via either a CLI param or the new snippet option :)

browser-sync . --no-snippet

or in any Browsersync configuration

const config = {
  snippet: false,
};

the original request was related to Eleventy usage, so here's how that would look

eleventyConfig.setBrowserSyncConfig({
  snippet: false,
});